Hinge last



Patented Apr. 7, 19254.

UNITED STATES WALTER A. KRENTLER, or DETROIT, MTQHIGAN.

HINGE LAST.

Application led June 21, 1922. Serial No, 568,463.

To all fic/20m 'it may concern.' f

Be' it known that I, VALTEH A. KnnN'n man, a citizen of the United States, and resident of Detroit, in the county of lVayne and State of Michigan, have invented an Improvement in Hinge Lasts, of which the following description, inv connection with the accompanying drawings, is av specification, like letters on the drawings representing like parts.

The present invention relates to boot Aand shoe lasts, and the object is to improve, simplify and perfect a hinge last construction.

A two-part or hinge last, while most desirable and in'iportant in the manufacture ofshoes, involves considerable expense and difficulty in the uniting or'hinge members, which are usually of pivotal or link construction. Furthern'iore, the cutting away of the wood of the forepart and heel part of the last develops weakness which limits the life of the last. Also the hinge or link devices to unite the last members wherein a plurality of parts constitute the hinge or link uniting elements, result in quickly developing looseness and wear and hence impair the continued utility of the last.

My present invention is directed to obviate these difhculties, to eliminate the cutting away ofthe wood of the lastl as much as possible, to provide an extremely simple pivotal construction, which in fact is a combined pivot and link-like uniting element and also to afford great strength as well as simplicity in the means joining the metallic uniting members to the woOd of the last. f

A feature consists in the ease and facility with which the last parts may be recessed or prepared to' receive the metallic hinge members and said hinge membersk will substantially fill the recess made. Thus I am enabled to bore into each part from the dividing line of cut, a recess which is quicklyy and easily formed, similar in effect to that of my prior Patent 1,094,153, dated April 21, 19M-which was prepared fo-rthe tubular hinge construction, and then this recess is filled by the present link construction and the cooperating spring or springs, thus securing the advantages of lateral support on the walls of the recess.

An additional advantage is that I am enabled to assemble my hinge parts prior to fitting them within the last and thus an complete the uniting of the last parts and hinge simply by driving 1n the two retaining rivets or pins in the extreme end portions of the link members at points remote from the line of cut. Further features, advantages, and novel combinations of parts will be hereinafter more fully pointed out 'and'claimed Referring to the drawings, i y Fig. l shows alast partlyin cross-section and in extended position;

Fig. 2 is a fragmentary and Ipartial crosssectional view of the last shown in broken,

shortened or flexed position; T

Fig. 3 is a cross-sectional view on the line 3 3 of Fig. l; and y F ig. t vis a similar cross-seotional view illustrating a modification wherein a plu(h rality of springs are employed, and wherein also the hinge members are assembled before tting of the last. Y

Referring to the drawings, the last consists of the wooden forepart l and heel part 2, preferably divided upon the line of cut to form the open faces 3 and 4, the knuckle lioint consisting in the concave face 5 in the fore-part and the'projecting knuckle 6 in the heel part, and the bottom blocking and bearing faces? and V8 in the forepart and heel part respectively. This is -a usual type of` construction. employing the knuckle jointhinge, and I prefer to employ the same in combination with my present type ofplurality of link or combined link and pivot construction. In the heel part I form a recess l0 andgin the forepart a somewhatl enlarged iecess`12, to receive the hinge members, and I also bore transverse recesses for the pins or rivets lli, l5 and 16.` Of theserivets thc central l5 is in the center 01 axis of the knuckle joint, and serves to act asA a pivotal hinge or pin on which the last parts themselves are fiexed. This pinl also serves to unite the' two link members 20 and 2l, which latter are plates bored to receive the pin 15 at their overlapping centers, and to receive. the pins 14tand 16 respectively at their ends.

In this form, as thus far described, the last with a plurality of links, will operate readily and easily, to be moved in either straightened or shortened position, and by positioning the link retaining pivots lei and 1G eccentrically with the central pivot 15 elo .purpose I provide the spring 25.

lthe last parts will snap ,or spring into either position, and lstay locked therein.

I-Iowever, I prefer to insure a positive means which will vexecute this action, and for this This f spring mayhave its end portions formed to engage the pivots lll and 16, kas shown in Figs. 1 and 2, and with its central or body v, -portion in a curve or convolute section ot suliicient extent to impart the desired'ie siliency and also'to clear the central `pivot with the last in extended position, as

shown in Fig. 1. This spring maybe either between the two links 2O and 21, as shown in Fig.. 3, or I may provide a plurality yot springs arranged each side of thel links 2() and 21, which latter are contiguous, as

shown in Fig. 4; Ineither instance the spring aids in holding the last parts at all f times in tightly assembledposition, in thus automaticallyy coi'i'ipensating lor any wear or looseness,'either along t'he faces 5 or 6, or at the rivet connections 14' and 16, as well as tor rlooseness or wear on the central pivot- 15,- The spr-ing or springs 25, also further' add-to greatly'increase the locking effect to t hold the last'parts irmlyin either sti-aight4 f pletely. assembled hingediiectly in the last,

ened or shortened position, and to require considerablev power to overcome the same and to snap or spring the 'last partsy by the' center. 4

l In order to have the hinge'meinbers assembled before fitting lthe same to the last, I may unite the links 2O and 21 with a short rivet 30, as shown in Fig. 4, thus saving the vboring through the knuckle joint for a long pivot or pin 15. AIn this manner I can asse'ii'iblethe two link members and lit the com- 'supplying .the spring or springs 25 and' driving in one rivet, for example 16, thus retaining all the saine in;position, thenfapplying the'torepart 1 and driving inthe remain-v ing rivet 14, or reversing this process. rThis feature of assembling the metallic elements outside of the assembling of the last, enables me to speed upthe construction and Jfurther saves the weakeningai'id boring throughthe vknuckle joint or ycentral part, while still insuring that the last parts will turn on the rivet 30 as well as'on the pivot 15',

AMy invention is further described and defined in the torni of claims as follows:

1. Atwo-part last, having a heel part and torepart formed and connected for relalast parts, said, Yremote securing means being disalined with regard to the s'aidf'pivotand knuckle joint feature y when the last lis in lengthened o'rgshortened position',- whereby the movement vot the last parts from lengthcned to shortened position o1 vice' versa will be against increasing resistance until said' remote uniting points are in alinement with t-he said center. y I i 3. A vhinge last of thekind described incl'udi-nga knuckle joint construction', a pivot pin passing transversely throu'gl'itheknuckle joint construction and acting as apivot about whichy `the `last parts are movable, av

plurality lof Alink members pi'votally con# nected at thev center ot the knuckle joint on said pivot pin 'and secured to the last parts at the opposite ends of saidlink members remote 'trom the line' ot cut of the last ,parts7 said remote securing means beiiig-di'salifgne'd with regard tothe said pivot-and l'-nuckl'e joint feature when the'la'st vis in leiigt'iened oi.'k shortened position whereby `iiiow'feinent of thegl'ast parts from lengthened to shortened position 4or vice versa will against i'nc'feasing resistance 1 untill said remote uniti/ng mean's are in alignment with the ysaid 4pivot and a resilient` spring connected to' there motese'curin'g means whereby the link i'i'ienivers are h e'ld together' under tension szuiiil cient to compensate for looseness and wea-r'.` Y In'testimony whereof, I have' sig-ned lmy naine to this sptcitication".`

i VL'IERA. KRENTLER. 

